THE EFFECT OF TWO LEVELS OF IRRIGATION ACCORDING TO THE STAGES OF GROWTH IN YELLOW MAIZE CROP (ZEA MAYS L.)

Abstract

A field experiment was carried out in autumn season2009 in one of the farmers' fields on the banks of Euphrates river in the city of Ramadi on yellow maize crop class (Abaa5018 Zea mays L), which is a newly derived synthetic variety in Iraqi agriculture, with the objective of studying the effect of two levels of irrigation of 75% and 50% of yellow maize crop plants with three stages of growth on the production of yellow maize in grain and dry matter.Seeds were sown on 15/07/2009 and harvested on 14/11/2009, the two levels of irrigation were distributed randomly over the stages of growth and eight coefficients were obtained.The stages of growth included the vegetative stage which begins from the date of isolation of irrigation coefficients on 1/8 till the onset of emergence of male inflorescence, the flowering stage which begins from the emergence of male inflorescence until the end of emergence of female inflorescence and then the last stage which begins from the end of second stage till the maturation of seedsThe coefficients of the experiment were randomly distributed and according to Randomized Complete Block Design (RCBD). While the irrigation coefficient (T8) which is irrigated by the second level of 50% throughout the season of growth gave the lowest rate for each of leaf area , dry matter, and grain harvest with water consumption of 276 mm. showed gradation in the production of grain, dry matter and leaf area, according to the distribution of irrigation water over the sensitive stages of growth for each character and are limited between the productions of irrigation coefficients (T1 & T8). They also varied in water consumption, total water requirement and water consumption efficiency. This variation occurred as a result of distribution of irrigation levels over the coefficients according to stages of growth.